Abstract: A radiation detector includes a semiconductor substrate having opposing front and rear surfaces, a cathode electrode located on the front surface of the semiconductor substrate configured so as to receive radiation, and a plurality of anode electrodes formed on the rear surface of said semiconductor substrate. A work function of the cathode electrode material contacting the front surface of the semiconductor substrate is lower than a work function of the anode electrode material contacting the rear surface of the semiconductor substrate.
Type:
Grant
Filed:
June 5, 2013
Date of Patent:
December 1, 2015
Assignee:
REDLEN TECHNOLOGIES
Inventors:
Henry Chen, Salah Awadalla, Pinghe Lu, Pramodha Marthandam
Abstract: A radiation detector includes a semiconductor substrate having opposing front and rear surfaces, a cathode electrode located on the front surface of the semiconductor substrate configured so as to receive radiation, and a plurality of anode electrodes formed on the rear surface of said semiconductor substrate. A work function of the cathode electrode material contacting the front surface of the semiconductor substrate is lower than a work function of the anode electrode material contacting the rear surface of the semiconductor substrate.
Type:
Grant
Filed:
February 2, 2009
Date of Patent:
December 24, 2013
Assignee:
Redlen Technologies, Inc.
Inventors:
Henry Chen, Salah Awadalla, Pinghe Lu, Pramodha Marthandam
Abstract: A method of making a semiconductor radiation detector includes the steps of providing a semiconductor substrate having front and rear major opposing surfaces, forming a solder mask layer over the rear major surface, patterning the solder mask layer into a plurality of pixel separation regions, and after the step of patterning the solder mask layer, forming anode pixels over the rear major surface. Each anode pixel is formed between adjacent pixel-separation regions and a cathode electrode is located over the front major surface of the substrate. The solder mask can be used as a permanent photoresist in developing patterned electrodes on CdZnTe/CdTe devices as well as a permanent reliability protection coating. The method is very robust and ensures long-term reliability, outstanding detector performance, and may be used in applications such as medical imaging and for demanding other highly spectroscopic applications.
Type:
Grant
Filed:
December 28, 2009
Date of Patent:
July 2, 2013
Assignee:
Redlen Technologies
Inventors:
Henry Chen, Pramodha Marthandam, Salah Awadalla, Pinghe Lu
Abstract: A radiation detector includes a semiconductor substrate which contains front and rear major surfaces and at least one side surface, a guard ring and a plurality of anode electrode pixels located over the rear surface of the semiconductor substrate, where each anode electrode pixel is formed between adjacent pixel separation regions, a side insulating layer formed on the at least one side surface of the semiconductor substrate, a cathode electrode located over the front major surface of the semiconductor substrate, and an electrically conductive cathode extension formed over at least a portion of side insulating layer, where the cathode extension contacts an edge of the cathode electrode. Further embodiments include various methods of making such semiconductor radiation detector.
Type:
Application
Filed:
April 20, 2012
Publication date:
October 25, 2012
Applicant:
Redlen Technologies
Inventors:
Henry Chen, Salah Awadalla, Pramodha Marthandam
Abstract: A device includes (a) radiation detector including a semiconductor substrate having opposing front and rear surfaces, a cathode electrode located on the front surface of said semiconductor substrate, and a plurality of anode electrodes on the rear surface of said semiconductor substrate, (b) a printed circuit board, and (c) an electrically conductive polymeric film disposed between circuit board and the anode electrodes. The polymeric film contains electrically conductive wires. The film bonds and electrically connects the printed circuit board and anode electrodes.
Abstract: A method of forming a passivation layer comprises contacting at least one surface of a wide band-gap semiconductor material with a passivating agent comprising an alkali hypochloride to form the passivation layer on said at least one surface. The passivation layer may be encapsulated with a layer of encapsulation material.
Abstract: A method is provided for fabricating contacts on semiconductor substrates by direct lithography that results in durable adhesion of the electrodes, increased interpixel resistance and the electrodes which act as a blocking contact, thereby providing for improved energy resolution in a resultant radiation detector.
Type:
Grant
Filed:
December 4, 2006
Date of Patent:
June 1, 2010
Assignee:
Redlen Technologies
Inventors:
Henry Chen, Serguei Roupassov, Salah Awadalla
Abstract: A radiation detector is described having a semiconductor substrate with opposing front and rear surfaces, a cathode electrode located on the front surface of said semiconductor substrate, a plurality of anode electrodes located on the rear surface of said semiconductor substrate and a solder mask disposed above the anode electrodes. The solder mask has openings extending to the anode electrodes for placing solder in said openings.
Abstract: A method is provided for compounding, homogenizing and consolidating compounds. In one embodiment, the charge components are mixed in a controlled addition process, then the newly-formed compound is heated to become totally molten, followed by a rapid quench at room temperature. In an alternate embodiment, the components are supplied with an excess of one component acting as a solvent, heated to dissolve additional components, and then the solvent is separated from the compound to produce homogeneous consolidated compounds. The methods herein are advantageously applied to provide an economical and fast process for producing CdTe, CdZnTe and ZnTe compounds.
Type:
Grant
Filed:
September 11, 2008
Date of Patent:
June 16, 2009
Assignee:
Redlen Technologies
Inventors:
Robert Francis Redden, Weidong Huang, Troy Oran Hasanen
Abstract: A radiation detector includes a semiconductor substrate with opposing front and rear surfaces, where a cathode electrode is located on the front surface, a plurality of anode electrodes located on the rear surface, and an electrically conductive housing is placed in electrical contact with the cathode electrode.
Type:
Grant
Filed:
April 17, 2007
Date of Patent:
December 9, 2008
Assignee:
Redlen Technologies
Inventors:
Henry Chen, Pinghe Lu, Ray Brougham, Salah Awadalla, Andrew MacDonald, Glenn Bindley
Abstract: A method is provided for compounding, homogenizing and consolidating compounds. In one embodiment, the charge components are mixed in a controlled addition process, then the newly-formed compound is heated to become totally molten, followed by a rapid quench at room temperature. In an alternate embodiment, the components are supplied with an excess of one component acting as a solvent, heated to dissolve additional components, and then the solvent is separated from the compound to produce homogeneous consolidated compounds. The methods herein are advantageously applied to provide an economical and fast process for producing CdTe, CdZnTe and ZnTe compounds.
Type:
Grant
Filed:
June 21, 2006
Date of Patent:
September 23, 2008
Assignee:
Redlen Technologies
Inventors:
Robert Francis Redden, Weidong Huang, Troy Oran Hasanen
Abstract: A semiconductor radiation detector is provided for improved performance of pixels at the outer region of the crystal tile. The detector includes a semiconductor single crystal substrate with two major planar opposing surfaces separated by a substrate thickness. A cathode electrode covers one of the major surfaces extending around the sides of the substrate a fraction of the substrate thickness and insulated on the side portions by an insulating encapsulant. An exemplary example is given using Cadmium Zinc Telluride semiconductor, gold electrodes, and Humiseal encapsulant, with the side portions of the cathode extending approximately 40-60 percent of the substrate thickness. The example with CZT allows use of monolithic CZT detectors in X-ray and Gamma-ray applications at high bias voltage. The shielding electrode design is demonstrated to significantly improve gamma radiation detection of outer pixels of the array, including energy resolution and photopeak counting efficiency.